scholarly journals Neuromuscular systems in the fifth instar larva of silkworm Bombyx mori (Lepidoptera: Bombycidae): I-Cephalothoracic musculature and its innervation

2009 ◽  
Vol 1 (2) ◽  
pp. 201-209
Author(s):  
S. Sivaprasad ◽  
P. Muralimohan

The cephalo-thoracic musculature of the fifth instar larva of Bombyx mori comprises distinct groups of segmental muscle bands arranged in a stereotyped pattern. It includes dorsal, ventral, tergopleural, tergocoxal, lateral intersegmental, pleurosternal, sternocoxal, pleurocoxal and spiracular muscles. The cephalothoracic segments are innervated by the nerves of brain, suboesophageal ganglion (SG) and three thoracic ganglia (TG1, TG2, TG3).The brain gives nerves for compound eyes, antennae, labrum, frontal ganglion and the integument in the head. The SG, TG1,TG2,and TG3 give out a pair of lateral segmental nerves each, called the dorsal (DN) and ventral (VN) nerves. The DN of SG innervates muscles in the cephalic region, while its VN innervates muscles in the prothorax. The DN of thoracic ganglia innervates muscles in the dorsal, lateral and ventral regions of the hemi-segment while the VN innervates muscles in the ventral region. The innervation pattern indicates the presence of mixed nerves and multiple innervations that facilitate coordinated body movements and locomotion.

1963 ◽  
Vol 40 (3) ◽  
pp. 517-530
Author(s):  
KINSAKU HASEGAWA

1. The action of the diapause hormone has been studied by injecting extracts of the heads of male moths or of the brain-suboesophageal ganglion complexes of pupae into pupae expected to produce non-diapause eggs. 2. The effect of the injection of hormone upon young oocytes is to make them develop into diapause eggs. Older oocytes, which have already acquired non-diapause characters, are not affected. 3. The hormone is almost completely inactivated when injected on the day of pupation. The hormone is most effective when injected into pupae 2-3 days old, at which stage the ovarioles have started to grow vigorously. It is ineffective 1-2 days before adult emergence, by which time all the oocytes have acquired non-diapause characters. 4. The hormone is inactivated in all pupae irrespective of whether they are destined to produce diapause eggs or non-diapause eggs. Inactivation of diapause hormone (in contrast to that of juvenile hormone) is partially relieved by exposure to low temperature or by simultaneous injection of indian ink. 5. The extracts prepared as in (1) above do not serve as a stimulant for the brain causing the suboesophageal ganglion to produce diapause hormone. The action of the extract faithfully reflects the function of the diapause hormone which originates in the suboesophageal ganglion.


2009 ◽  
Vol 1 (2) ◽  
pp. 210-226
Author(s):  
S. Sivaprasad ◽  
P. Muralimohan

The gross organisation of abdominal musculature and its innervation by segmental ganglionic nerves were studied in the fifth instar larva of Bombyx mori. The musculature comprises dorsal, ventral and lateral groups of muscles, represented as external and internal layers. The dorsal group includes musculi dorsales interni mediales (DIM), musculi dorsales externi mediales (DEM), musculi dorsales interni laterals (DIL) and musculi dorsales externi laterales (DEL). The ventral group includes musculi ventrales interni mediales (VIM), musculi ventralesexterni mediales (VEM), musculi ventrales interni laterales (VIL) and musculi ventrales externi laterales (VEL). The lateral group is represented by musculi laterales interni (LI) and musculi laterales externi (LE). The abdominal muscles are innervated by the dorsal (DN) and ventral (VN) nerves of abdominal ganglia. The DN innervates ventral internal, lateral internal and both dorsal external and internal muscles, while the VN innervates ventral external and lateral muscles. The sensory branches of DN and VN innervate the bodywall in the dorsal and ventral regions respectively with a sort of overlapping in the lateral region. The neuromuscular integration and intersegmental coordination in the abdominal region is discussed with reference to locomotion in the silkworm larva.


1986 ◽  
Vol 64 (12) ◽  
pp. 2669-2673 ◽  
Author(s):  
B. Duff Sloley ◽  
Roger G. H. Downer ◽  
Cedric Gillott

Tryptophan, 5-hydroxytryptamine, and dopamine were measured in the frontal ganglion, corpora cardiaca, corpora allata, nerves of the suboesophageal ganglion, nerves of the thoracic ganglia, gut, testes, and ovaries of the cockroach Periplaneta americana using high performance liquid chromatography with electrochemical detection. 5-Hydroxytryptamine was demonstrated in the frontal ganglion, corpora cardiaca, corpora allata, and nerves of the suboesophageal ganglion but not in the gut, testes, ovaries, or nerves of the thoracic ganglia. These results quantitatively confirm immunohistochemical studies of 5-hydroxytryptamine in neurohaemal and nonneuronal tissues of the cockroach. Dopamine was found in all neurohaemal and nervous tissue examined. Dopamine was also found at low levels in the rectum. Tryptophan was found in all tissues examined.


1973 ◽  
Vol 19 (4) ◽  
pp. 857-859 ◽  
Author(s):  
Masatoshi Kobayashi ◽  
Masayoshi Yamazaki ◽  
Shigeru Kimura

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